From 5420a70572bbcc3c4051483c9f33814c2977c05e Mon Sep 17 00:00:00 2001
From: Patrice Mandin <patmandin@gmail.com>
Date: Sat, 30 Sep 2017 22:06:30 +0200
Subject: [PATCH] atari:gem: Align window content on 16 pixels boundary (faster
 for bitplanes modes). Make GEM_clear_rect public function to clear the
 visible extra space.

---
 src/video/gem/SDL_gemevents.c | 32 ++++++++++++++++++++++++++------
 src/video/gem/SDL_gemvideo.c  |  7 +++----
 src/video/gem/SDL_gemvideo.h  |  1 +
 3 files changed, 30 insertions(+), 10 deletions(-)

diff --git a/src/video/gem/SDL_gemevents.c b/src/video/gem/SDL_gemevents.c
index 401b8891d..61cf1b292 100644
--- a/src/video/gem/SDL_gemevents.c
+++ b/src/video/gem/SDL_gemevents.c
@@ -187,9 +187,9 @@ void GEM_PumpEvents(_THIS)
 
 static int do_messages(_THIS, short *message, short latest_msg_id)
 {
-	int quit, update_work_area, sdl_resize;
+	int quit, update_work_area, align_work_area, sdl_resize;
 
-	quit = update_work_area = sdl_resize = 0;
+	quit = update_work_area = align_work_area = sdl_resize = 0;
 	switch (message[0]) {
 		case MSG_SDL_ID:
 			quit=(message[1] == latest_msg_id);
@@ -201,7 +201,7 @@ static int do_messages(_THIS, short *message, short latest_msg_id)
 			break;
 		case WM_MOVED:
 			wind_set(message[3],WF_CURRXYWH,message[4],message[5],message[6],message[7]);
-			update_work_area = 1;
+			update_work_area = align_work_area = 1;
 			break;
 		case WM_TOPPED:
 			wind_set(message[3],WF_TOP,message[4],0,0,0);
@@ -249,11 +249,11 @@ static int do_messages(_THIS, short *message, short latest_msg_id)
 					0,0);
 				GEM_refresh_name = SDL_FALSE;
 			}
-			update_work_area = 1;
+			update_work_area = align_work_area = 1;
 			break;
 		case WM_SIZED:
 			wind_set (message[3], WF_CURRXYWH, message[4], message[5], message[6], message[7]);
-			update_work_area = sdl_resize = 1;
+			update_work_area = align_work_area = sdl_resize = 1;
 			GEM_win_fulled = SDL_FALSE;		/* Cancel maximized flag */
 			GEM_lock_redraw = SDL_TRUE;		/* Prevent redraw till buffers resized */
 			break;
@@ -272,7 +272,7 @@ static int do_messages(_THIS, short *message, short latest_msg_id)
 					GEM_win_fulled = SDL_TRUE;
 				}
 				wind_set (message[3], WF_CURRXYWH, x, y, w, h);
-				update_work_area = sdl_resize = 1;
+				update_work_area = align_work_area = sdl_resize = 1;
 				GEM_lock_redraw = SDL_TRUE;		/* Prevent redraw till buffers resized */
 			}
 			break;
@@ -289,6 +289,26 @@ static int do_messages(_THIS, short *message, short latest_msg_id)
 
 	if (update_work_area) {
 		wind_get (message[3], WF_WORKXYWH, &GEM_work_x, &GEM_work_y, &GEM_work_w, &GEM_work_h);
+
+		/* Align work area on 16 pixels boundary (faster for bitplanes modes) */
+		if (align_work_area) {
+			int aligned_x;
+			short pxy[4];
+
+			aligned_x = GEM_work_x;
+			if (aligned_x & 15) {
+				aligned_x = (aligned_x|15)+1;
+
+				pxy[0] = GEM_work_x;
+				pxy[1] = GEM_work_y;
+				pxy[2] = aligned_x - 1;
+				pxy[3] = pxy[1] + GEM_work_h - 1;
+				GEM_clear_rect(this, pxy);
+			}
+			GEM_work_w -= (aligned_x - GEM_work_x);
+			GEM_work_x = aligned_x;
+		}
+
 		if (sdl_resize) {
 			SDL_PrivateResize(GEM_work_w, GEM_work_h);
 		}
diff --git a/src/video/gem/SDL_gemvideo.c b/src/video/gem/SDL_gemvideo.c
index 0504c4d00..de9d0fc7f 100644
--- a/src/video/gem/SDL_gemvideo.c
+++ b/src/video/gem/SDL_gemvideo.c
@@ -93,7 +93,6 @@ static void GEM_UpdateRects(_THIS, int numrects, SDL_Rect *rects);
 /* Internal functions */
 static void GEM_FreeBuffers(_THIS);
 static void GEM_ClearScreen(_THIS);
-static void GEM_ClearRect(_THIS, short *rect);
 static void GEM_SetNewPalette(_THIS, Uint16 newpal[256][3]);
 static void GEM_LockScreen(_THIS);
 static void GEM_UnlockScreen(_THIS);
@@ -500,7 +499,7 @@ static void GEM_FreeBuffers(_THIS)
 	}
 }
 
-static void GEM_ClearRect(_THIS, short *rect)
+void GEM_clear_rect(_THIS, short *rect)
 {
 	short oldrgb[3], rgb[3]={0,0,0};
 
@@ -524,7 +523,7 @@ static void GEM_ClearScreen(_THIS)
 	pxy[0] = pxy[1] = 0;
 	pxy[2] = VDI_w - 1;
 	pxy[3] = VDI_h - 1;
-	GEM_ClearRect(this, pxy);
+	GEM_clear_rect(this, pxy);
 
 	v_show_c(VDI_handle, 1);
 }
@@ -1204,7 +1203,7 @@ static void refresh_window(_THIS, int winhandle, short *rect)
 
 		surface = GEM_icon;
 
-		GEM_ClearRect(this, rect);
+		GEM_clear_rect(this, rect);
 
 		/* Calculate centered icon(x,y,w,h) relative to window */
 		iconx = (wind_pxy[2]-surface->w)>>1;
diff --git a/src/video/gem/SDL_gemvideo.h b/src/video/gem/SDL_gemvideo.h
index 9a507666b..6fc27b35c 100644
--- a/src/video/gem/SDL_gemvideo.h
+++ b/src/video/gem/SDL_gemvideo.h
@@ -37,6 +37,7 @@ struct WMcursor {
 
 /* Functions prototypes */
 void GEM_wind_redraw(_THIS, int winhandle, short *inside);
+void GEM_clear_rect(_THIS, short *rect);
 
 /* Private display data */